From the past, image display apparatuses such as projectors are being widely used. For example, light from a light source is modulated by a light modulation element such as a liquid crystal element, and modulated light is projected on a screen or the like, thereby displaying an image. As the light source, a mercury lamp, a xenon lamp, an LED (Light Emitting Diode), an LD (Laser Diode), or the like is used. Out of those, a solid light source such as an LED and an LD has advantages in terms of a long lifetime that can save a lamp exchange unlike before and instantaneous lighting when a power is turned on.
Patent Literature 1 describes, as shown in FIG. 1 thereof, a projector including a mercury lamp and a mirror device capable of selectively reflecting light from the mercury lamp in two directions. In the projector, on a basis of a luminance distribution of image signals and an image average luminance thereof, an operation of the mirror device is controlled, and a light quantity of light with which a light modulation apparatus for each of RGB is irradiated is controlled. Specifically, in a case where an input gradation of the light modulation apparatus is low, and a pixel difficult to reproduce a color exists, the quantity of light with which the light modulation apparatus is irradiated is reduced. Meanwhile, the input gradation of the light modulation apparatus is changed to be such a high gradation value that color reproduction can be appropriately performed. As a result, even in a case of a black image or an image with a low luminance, it is possible to obtain a projection image with good color reproduction (paragraph [0034] of the description, FIG. 7, and the like in Patent Literature 1).